package com.dp.utils;

import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock{
    private StringRedisTemplate stringRedisTemplate;
    private String name;
    public static final String KEY_PREFIX ="lock:";
    public static final String ID_PREFIX = UUID.randomUUID().toString()+ "-";
    public static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT= new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    public SimpleRedisLock(StringRedisTemplate stringRedisTemplate, String name) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.name = name;
    }

    @Override
    public boolean tryLock(Long timeoutSet) {
        //获取线程标识
        String ThreadId = ID_PREFIX+Thread.currentThread().getId();
        //获取锁
        Boolean success = stringRedisTemplate.opsForValue()
                .setIfAbsent(KEY_PREFIX+name,ThreadId, timeoutSet, TimeUnit.SECONDS);
        return  Boolean.TRUE.equals(success) ;
    }




    @Override
    public void unLock() {
        //基于lua脚本实现释放锁

        //调用lua脚本
        stringRedisTemplate.execute(
                UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX+name),
                ID_PREFIX+Thread.currentThread().getId()
        );
    }

//    @Override
//    public void unLock() {
//        //获取线程标识
//        String ThreadId = ID_PREFIX+Thread.currentThread().getId();
//
//        //获取锁标识
//        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//        //判断是否一致
//        if (ThreadId.equals(id)) {
//            //一致就是自己的锁，直接释放
//            //释放锁
//            stringRedisTemplate.delete(KEY_PREFIX+name);
//        }
//
//    }
}
